# FLUX.2 Klein ComfyUI Guide: Set Up and Edit Images Locally > Published 2026-04-01, updated 2026-09-05 · https://www.promptzone.com/astrid_hartley/flux-2-klein-edit-enhanced-ai-image-generation-in-comfyui-3kb0 --- title: "FLUX.2 Klein ComfyUI Guide: Set Up and Edit Images Locally" published: true description: "Edit images with FLUX.2 Klein in ComfyUI using the official distilled 4B workflow, matching model files, and clear preservation prompts." tags: ai,comfyui,imagegeneration,flux --- To edit images with FLUX.2 Klein in ComfyUI, load the official editing template, select its model files, and supply a source image and edit instruction. Klein is Black Forest Labs’ generation and editing model family, with downloadable checkpoints for local workflows. [ComfyUI guide][comfy], [Official workflow][workflow] This walkthrough uses the distilled 4B template for Klein’s built-in editing capability. [Official workflow][workflow] ## What are the key facts about FLUX.2 Klein in ComfyUI? | Field | Verified detail | | --- | --- | | Developer | Black Forest Labs develops Klein; ComfyUI publishes the workflow. [Release][launch], [Workflow][workflow] | | Released | Original Klein family: January 15, 2026. [Release][launch] | | Type | Text-to-image and image editing with reference inputs. [4B card][card] | | Size or parameters | This tutorial uses the 4B image transformer; the family also includes 9B models. [Release][launch] | | License and access | Klein 4B weights: Apache 2.0. Klein 9B uses the FLUX Non-Commercial License. [Model overview][models] | | Where it runs | Local ComfyUI with the matching weights; hosted BFL access is also available separately. [ComfyUI guide][comfy], [4B card][card] | ## Which image edits can FLUX.2 Klein make in ComfyUI? ComfyUI documents object replacement or removal, style changes, semantic edits, and iterative editing for Klein. It offers separate templates for Base and distilled checkpoints. [ComfyUI guide][comfy] The practical benefit is a saved graph whose input image, instruction, and model choices remain visible. Use that graph as a record of a particular edit so you can review the result against the original. Begin with a narrow task such as changing the color of a chair while keeping the room layout. Write the requested alteration first, followed by the features you need preserved. For example: “Change the chair upholstery to dark green. Keep the chair frame, floor, surrounding furniture, camera position, and lighting.” This is an original test instruction, not a guaranteed result. BFL’s reference guidance recommends being explicit about what each image contributes when combining inputs. Extend your workflow only after you can explain the intended role of every reference. [Reference guide][references] For more wording examples, use the sibling [Klein prompting guide](/farrah_saleh/flux-2-klein-a-new-benchmark-in-ai-image-generation-4blm). Save an unchanged copy of the starter graph before experimenting. ## What can go wrong with FLUX.2 Klein image edits? Klein can miss prompt requirements and distort rendered text, according to its model card. Inspect labels, hands, repeated objects, and any content that your instruction asked it to preserve. [4B card][card] A successful render only establishes that the graph executed. Accept the edit after checking that the requested change occurred and that the rest of the image still meets your needs. The checkpoints and encoders differ across sizes. ComfyUI’s 4B setup uses a Qwen 3 4B encoder; its 9B setup lists a Qwen 3 8B encoder instead. [ComfyUI guide][comfy] Use the files named by your chosen workflow. If you switch to another template, compare its embedded download notes before reusing files from an existing installation. Performance also depends on the checkpoint and runtime configuration. BFL’s product table reports separate figures for Base and distilled models on specified hardware. [Model overview][models] Treat those figures as configuration-specific measurements. Record your own first run and subsequent edit times if interactive latency is important to your project. ## How do you set up the Klein 4B editing workflow in ComfyUI? 1. Update ComfyUI through the update method for your installation. The official Klein guide explains that missing templates or core nodes can indicate an outdated build or a failed startup import. [ComfyUI guide][comfy] 2. Open the official Klein guide and select the distilled 4B image-editing workflow. Download the JSON or find the matching workflow in the templates interface. [ComfyUI guide][comfy] 3. Download the files named in that workflow’s model notes. For the inspected template, these are the diffusion model, Qwen text encoder, and FLUX.2 VAE shown below. [Workflow][workflow] ```text ComfyUI/models/diffusion_models/flux-2-klein-4b-fp8.safetensors ComfyUI/models/text_encoders/qwen_3_4b.safetensors ComfyUI/models/vae/flux2-vae.safetensors ``` 4. Load the template and select those files in its model controls. Supply your source picture in the image input, enter the edit instruction, and retain the template’s initial sampling settings. The JSON also contains a multiple-input example; supply its reference images if you enable that group. [Workflow][workflow] 5. Run the workflow, inspect the output, and save the graph alongside your selected result. ComfyUI supports saving and loading workflows for later use. [ComfyUI repository][app] For an already installed manual checkout with dependencies configured, ComfyUI’s documented launch command is: [ComfyUI repository][app] ```bash python main.py ``` Use your installation’s normal launcher for Desktop or portable packages. The command above assumes you are inside a configured manual checkout; it does not install dependencies or download weights. [ComfyUI repository][app] Before editing your own photograph, consider running the supplied template as closely as possible to its documented setup. Keep the first successful graph as a baseline for diagnosing later changes. If a model selector is empty, compare the intended filename and folder with the workflow notes. Check the diffusion model, encoder, and VAE individually instead of assuming the diffusion file contains everything. If a node is missing, read the startup error and check your ComfyUI version. The guide identifies version lag and import failures as possible causes. [ComfyUI guide][comfy] When the graph runs but the image is wrong, revise one requirement at a time. Separate replacing the background from changing the lighting, or recoloring an object from altering its shape. For an edit series, keep the original image and each accepted intermediate result. Compare later outputs to the original as well as the previous step so that subtle changes remain visible. ## How do Klein editing workflows compare? | Workflow | Reason to consider it | | --- | --- | | Klein 4B distilled | A supported editing template using a short sampling schedule. [ComfyUI guide][comfy] | | Klein 4B Base | An undistilled option intended for flexibility and training. [Release][launch] | | Klein 9B | Another supported size with different encoder files and weight licensing. [ComfyUI guide][comfy] | Compare complete workflows using the same source picture and instruction. Keep their checkpoint-specific settings intact for the initial comparison. The [ComfyUI pillar](/tomas_novak/comfyui-2026-the-complete-guide-to-power-user-ai-image-generation-1g17) covers graph organization and the wider workflow interface. ## What else should you know about Klein editing in ComfyUI? ### Which FLUX.2 Klein checkpoint supports image editing? FLUX.2 Klein checkpoints support generation and reference editing; the official ComfyUI walkthrough here uses distilled Klein 4B. Load the image-editing template for that checkpoint and follow its component list. [4B card][card], [Workflow][workflow] ### Do I need custom nodes for the official Klein template? The inspected FLUX.2 Klein 4B editing template uses ComfyUI core nodes. Update ComfyUI and investigate startup import errors if those nodes are missing. [Workflow][workflow], [ComfyUI guide][comfy] ### Can Klein 4B and 9B use the same text encoder? The documented FLUX.2 Klein ComfyUI setups use Qwen 3 4B for the 4B model and Qwen 3 8B for the 9B model. Follow the selected template’s file list when switching checkpoints. [ComfyUI guide][comfy] ### Can FLUX.2 Klein preserve every detail during an edit? FLUX.2 Klein’s model card warns that output may fail to match the prompt. State which features should remain and compare the complete edited image with the source. [4B card][card] ## Sources - [Klein release announcement][launch] - [ComfyUI Klein workflows and downloads][comfy] - [Official distilled 4B editing workflow][workflow] - [Klein 4B model card][card] - [Klein model comparison][models] - [BFL reference editing instructions][references] - [ComfyUI installation and workflow documentation][app] [launch]: https://bfl.ai/blog/flux2-klein-towards-interactive-visual-intelligence [comfy]: https://docs.comfy.org/tutorials/flux/flux-2-klein [workflow]: https://github.com/Comfy-Org/workflow_templates/blob/main/templates/image_flux2_klein_image_edit_4b_distilled.json [card]: https://huggingface.co/black-forest-labs/FLUX.2-klein-4B [models]: https://bfl.ai/models/flux-2-klein [references]: https://docs.bfl.ai/guides/prompting_editing_multi_reference [app]: https://github.com/Comfy-Org/ComfyUI ## Related guides on PromptZone - [ComfyUI 2026: The Complete Guide](/tomas_novak/comfyui-2026-the-complete-guide-to-power-user-ai-image-generation-1g17) - [How to Install and Run SDXL Models in ComfyUI](/jaroslav/how-to-install-and-run-sdxl-models-in-comfyui-a-complete-guide-2nk2) - [How to Use LoRAs in ComfyUI in 2026](/tara_suzuki/how-to-use-loras-in-comfyui-in-2026-load-stack-and-troubleshoot-235e)